Enthalpies of combustion and formation of fullerenes by micro-combustion calorimetry in a Calvet calorimeter

The thermochemistry of coronene revisited

“…These data were required for the calculation of the standard enthalpy of combustion and sublimation. Solid Vaseline (Fluka) and natural cotton were used as combustion promoters, with chemical composition, massic heat capacities, and energies of combustion previously determined [17,18]. The respective densities and Àð@U=@PÞ T values for these promoters were taken from the literature [23].…”

“…The energy of combustion for coronene was measured using a micro-bomb set associated with a Setaram C80 Calvet calorimeter operating in isothermal mode [17,18]. Two flux meters, with a power detection limit of 2 lW and a calorimetric resolution of 0.1 lW, served as the sensors of the calorimeter.…”

“…To ensure a well-defined thermodynamic equilibrium at the end of the combustion in all the calibration and measurement experiments, 1.1 lmol of de-mineralised water was placed into the bomb. Removal of the air inside the micro-bomb and charging it with oxygen to 3.04 MPa was performed as previously described [17,18]. The micro-bomb, serving as a calorimetric reference, was prepared exactly in the same way as described above; however, no combustion experiment was performed inside.…”

“…After each combustion experiment, qualitative analysis of the gas phase was performed by Dräger tubes as described previously [17,18]. No evidence of carbon monoxide or nitrogen oxides was found.…”

“…For example, the energy of combustion of this polycyclic hydrocarbon is quantified by applying an already described micro-combustion method [17,18] that involves a mass of sample of around two milligrams per experiment. The combustion data for coronene were verified by conventional isoperibol combustion calorimetry, finding a very good agreement with the expected uncertainties of both techniques.…”